If the minimum still exists, it’s what you need to have earned in Rewards before you can link/send it over to Uphold.
I say “if it still exists” because there was a time it had been talked of getting rid of the minimum required. Yet also was a time they needed more than 2 BAT, so it’s possible they just lowered the amount needed rather than eliminate.
Gemini can be a pain, but how is it you’ve been struggling with Brave support? I just looked and haven’t seen you post anything here before today.
NOTE
Btw, it might help if you want to take the time and read everything in the FAQ I made, which addresses some more common questions and issues. You can see it at -Retired- PSA: User FAQ - Support & Answers